Central to the operation was the destruction of fish-oil production and stores which the Germans used in the manufacture of high explosives. Another intention was to cause the Germans to maintain and increase forces in Norway which otherwise might be employed on the Eastern Front.

The dawn landing was preceded by a very effective naval bombardment and objectives went according to plan except in the town of Måløy itself. Opposition there was much stiffer than expected as, unknown to the British, a Gebirgsjäger (mountain rangers) unit of experienced troops from the Eastern Front was there on leave.

Their experience in sniping and street fighting caused the operation to develop into a bitter house-to-house battle. This caused the commander, John Durnford-Slater, to call in the floating reserve and troops from Vågsøy Island. A number of local citizens assisted the commandos by acting as porters for ammunition, grenades and other explosives, and in carrying away the wounded.

At around 14:00, the commandos started their withdrawal having destroyed four factories, the fish-oil stores, ammunition and fuel stores, the telephone exchange and various military installations. Much of the town was in flames. The naval assault force of one cruiser and four destroyers had meanwhile sunk 10 vessels, some found in the act of being scuttled to prevent capture.

No Royal Navy ships were lost, but the navy suffered four men killed and four wounded. The Commandos sustained 17 killed and 53 wounded, the commander of the exiled Norwegians, Capt. Linge, was killed in an attack on the local German headquarters, and the Royal Air Force had eight planes downed. (A single Norwegian civilian was killed during the raid, probably by shrapnel.) The commandos accounted for at least 120 enemy killed and returned with 98 prisoners and a complete copy of the German Naval Code. Captain O'Flaherty seen here was hit by sniper fire. He lost one eye and subsequently became a Brigadier wearing an eyepatch. Several Quislings and a number of loyal Norwegians were also brought back. In conjunction with this raid, Operation Anklet was mounted by No. 12 Commando on the Lofoten Islands as a diversion.

The raid was enough to persuade Adolf Hitler to divert 30,000 troops to Norway and to upgrade coastal and inland defences. Hitler thought that the British might invade northern Norway to put pressure on Sweden and Finland.